Multi-layer laminates of constituent material (e.g., carbon fiber) may be formed into any of a variety of shapes for curing into a composite part. To facilitate the fabrication of composite parts, a robot such as an Automated Fiber Placement (AFP) machine may be utilized. For example, an AFP machine may lay up a layer of tows of constituent material, which are then cured. After curing has completed, another layer may be laid-up by the AFP machine. In this manner, the composite part is fabricated as a series of layers over a period of time.
The operations of an AFP machine may be directed by a Numerical Control (NC) program that dictates movements of the AFP machine as tow layup continues. An AFP machine may dispense multiple tows at once in a single course, and an AFP machine may initiate or terminate individual tows within a course in response to instructions from the NC program.
While an NC program provides instructions for laying up material for a composite part in an ideal environment, some tows dispensed by an AFP machine may be placed outside of their intended locations (e.g., offset by some small amount) during the layup process. For example, unexpected forces applied by dressing/cabling surrounding the robot, or minor imperfections in the actuators that drive the robot, may cause inaccuracies when repositioning the robot. These inaccuracies may in turn result in out of tolerance inconsistencies at the laminate as tows are placed in non-optimal locations. For a large composite part (e.g., an aircraft fuselage), it may be difficult for an operator of an AFP machine to access or otherwise view tows of material as they are laid-up. Furthermore, a manual inspection process may result in delays that are incurred each time a new layer of tows is laid-up. Hence, operators of AFP machines continue to desire enhanced systems capable of detecting and reporting inconsistencies that are outside of tolerance that occur during the layup process.